Thermosettable epoxy resin composition

Abstract

Disclosed are thermosettable compositions comprising (A) an epoxy resin such as the diglycidyl ether of bisphenol A; (B) boron trifluoride complexed with a primary, secondary or tertiary amine such as monoethanolamine and (C) at least one cyclic or acyclic phosphazene having at least one pendant ##STR1## group wherein Z is an alkyl or an aryl group such as hexa(n-propylamino)cyclotriphosphazene. When cured, these compositions have an increased glass transition temperature (Tg) value as compared to a similar composition without the phosphazene compound. These compositions are useful in potting compositions, wet lay-up and pre-impregnated laminate, adhesive, molding, coating, casting, encapsulation, filament winding and transfer molding applications.

We claim: 
     
       1. A thermosettable epoxy resin composition which comprises (A) an epoxy resin having an average of more than one vicinal 1,2-epoxy groups per molecule or a mixture thereof;   (B) at least one boron trifluoride complex of a primary, secondary or tertiary amine or combination thereof; and   (C) at least one acyclic or cyclic phosphazene compound having at least one pendant ##STR6## group wherein Z is a hydrocarbyl or a halogen substituted hydrocarbyl group having from about 1 to about 20 or a--Q--O--Q') n  or a --Q--S--Q') n  group wherein each Q and Q' is independently a divalent hydrocarbyl or halogen substituted hydrocarbyl group wherein the total number of carbon atoms in the Q and Q' groups is from 2 to about 20 and n has a value from 1 to about 10; wherein component (B) is employed in an amount of from about 2 to about 10 parts per one hundred parts by weight of component (A); component (C) is employed in an amount which provides an improvement in the glass transition temperature of the composition when cured but a quantity less than that quantity which results in decomposition of the resin mixture during cure and wherein a mixture consisting only of components (A), (B) and (C) forms a homogeneous composition at a temperature below which gelation of the mixture occurs.     
     
     
       2. A composition of claim 1 wherein component (B) is employed in an amount of from about 3 to about 5 parts per one hundred parts by weight of component (A); component (C) is employed in an amount of from about 3 to about 25 parts per one hundred parts by weight of component (A). 
     
     
       3. A composition of claim 2 wherein component (B) is boron trifluoride complexed with (a) an alkylamine having from 1 to about 6 carbon atoms, (b) a dialkylamine having from 1 to about 6 carbon atoms in each alkyl group, (c) a trialkylamine having from about 1 to about 6 carbon atoms in each alkyl group, (d) an alkanolamine having from 1 to about 6 carbon atoms, (e) a dialkanolamine having from 1 to about 6 carbon atoms in each alkyl group, (f) a trialkanolamine having from about 1 to about 6 carbon atoms in each alkyl group, (g) an aryl amine having from about 6 to about 12 carbon atoms, (h) an N-alkyl aryl amine having a total of from about 7 to about 15 carbon atoms (i) any combination of any two or more of (a) through (h). 
     
     
       4. A composition of claim 3 wherein component (C) is employed in an amount of from about 10 to about 24 parts per one hundred parts by weight of component (A) and component (A) is a diglycidyl ether of bisphenol A, a diglycidyl ether of tetrabromobisphenol A or a mixture thereof; component (B) is boron trifluoride.2-aminoethanol complex, boron trifluoride.diethylamine complex, boron trifluoride.N,N-dimethylaniline complex or combination thereof and component (C) is hexa(n-propylamino)cyclotriphosphazene, octa(n-propylamino)cyclotetraphosphazene, chloropenta(n-butylamino)cyclotriphosphazene or combination thereof. 
     
     
       5. A product resulting from curing a composition of claim 1. 
     
     
       6. A product resulting from curing a composition of claim 2. 
     
     
       7. A product resulting from curing a composition of claim 3. 
     
     
       8. A product resulting from curing a composition of claim 4.